ML17164A821
| ML17164A821 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 10/05/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML17164A819 | List: |
| References | |
| NUDOCS 9810140103 | |
| Download: ML17164A821 (6) | |
Text
~
~R Ropy
~4
~o 0O lA O~
~O
+**++
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.c. 20555-0001 SAFETY EVALUATIONBYTHE OFFICE OF NUCLEAR REACTOR REGULATION RELATEDTO THE INSERVICE TESTING PROGRAM REVISIONS PENNSYLVANIAPOWER AND LIGHTCOMPANY SUS UEHANNASTEAM ELECTRIC STATION UNITS 1 AND2 DOCKET NOS. 50-387 AND 50-388
1.0 INTRODUCTION
The Code ofFederal Regulations, 10 CFR 50.55a, requires that inservice testing (IST) of certain American Society of Mechanical Engineers (ASME) Code Class 1, 2, and 3 pumps and valves be performed in accordance with Section XI of the ASME Boilerand Pressure Vessel Coda (the Code) and applicable addenda, except where alternatives have been authorized or relief has been requested by the licensee and granted by the Commission pursuant to sections (a)(3)(i),
(a)(3)(ii), or (f)(6)(i) of 10 CFR 50.55a.
In proposing alternatives or requesting relief, the licensee must demonstrate that: (1) the proposed alternatives provide an acceptable level of quality and safety; (2) compliance would result in hardship or unusual difficultywithout a compensating increase in the level of quality and safety; or (3) conformance is impractical for its facility.
Section 50.55a authorizes the Commission to approve alternatives and to grant relief from ASME Code requirements upon making the necessary findings. Additionally, 50.55a(f)(4)(iv) of Section 50.55a provides that IST of pumps and valves may meet the requirements set forth in subsequent editions and addenda of the Code that are incorporated by reference in paragraph (b) of Section 50.55a, subject to the limitations and modifications listed therein, and subject to Commission approval.
Portions of editions and addenda may be used provided that all related requirements of the respective editions or addenda are met. Guidance related to the development and implementation of IST programs is given in Generic Letter (GL) 89-04, "Guidance on Developing Acceptable Inservice Testing Programs," issued April3, 1989, and its Supplement 1 issued April4, 1995. Also see NUREG-1482, "Guidelines for Inservice Testing at Nuclear Power Plants."
. The 1989 Edition of the ASME Code is the latest edition incorporated by reference in paragraph (b) of Section 50.55a.
Subsection IWVof the 1989 Edition, which gives the requirements for IST of valves, references Part 10 of the American National Standards Institute/ASME Operations and Maintenance Standards (OM-10) as the rules for IST of valves.
OM-10 replaces specific requirements in previous editions of Section XI, Subsection IWV, of the ASME Code.
Subsection IWP of the 1989 Edition, which gives the requirements for IST of pumps, references Part 6 of the American National Standards Institute/ASME Operations and Maintenance Standards (OM4) as the rules for IST of pumps.
OMR replaces specific requirements in previous editions of Section XI, Subsection IWP, of the ASME Code.
9810140103 981005 PDR
- DOCK 05000387 P
0 By letter dated July 27, 1998, Pennsylvania Power and Light Company (PP&L) submitted Revision 16 for'Unit 1 and Revision 13 for Unit 2 to the Susquehanna Steam Electric Station Inservice Inspection Program Plan for Pump and Valve Operational Testing. The NRC staff has completed its review of the licensee's submittal and finds there are no new requests for relief from ASME Boiler and Pressure Vessel Code,Section XI, requirements in the submittal. The licensee has revised several relief requests that had been previously approved by the staff. The revision changed the test intervals for check valve groupings based on a 24-month refuel cycle versus an 18-month refuel cycle.
3.0 E
U TON SED I
The NRC staff reviewed its previously issued safety evaluations for those relief requests where this change could potentially affect its conclusions.
The staff finds the changes do not affect the validity of the relief requests and alternatives previously granted and authorized by the staff for the current 120-month interval. However, the staff finds that cIarification of previously-issued safety evaluations is needed to ensure that the change from the 18-month to 24-month refuel cycle has been adequately considered in the staff's evaluation of the relief requests.
For relief requests 1RR01, 1RR02, 1RR09, 1RR18, 1RR19, 1RR20, 1RR26, 1RR27, 2RR09, 2RR18, 2RR20, 2RR24, 2RR26, and 2RR27, the change to the refuel cycle from 18 to 24 months affected the test intervals for certain check valve groupings such that each valve 'would be tested once every 8 years (96 months) instead of once every 6 years (72 months). The staff noted in Position 2 of Generic Letter 89-04, "Guidance on Developing Acceptable Inservice Testing Programs,"
that when test intervals are extended beyond 6 years, additional information to document the valves'ondition and functional capability would be needed to support the extension.
This statement in the generic letter gas raised questions in the past for those plants on a 24-month refuel cycle. The staff's intent was to tie the test interval to a maximum of four refueling cycles.
Hence, the staff also acknowledged in Position 2 of GL 89-04 that, when the refuel cycle is increased to 24 months, each valve in a four-valve sample group woiild be tested only once every 8 years.
Although the staff noted in GL 89-04 that extending test intervals longer than 6 years should only be considered in cases of extreme hardship and should be supported with additional information, it was the staff's intention to allow test intervals up to 8 years (four refueling cycles) for each valve in a group size of four for those plants on a 24-month refuel cycle without any additional justification. Furthermore, extending the test interval from 6 years to 8 years is justified based on the check valve failure rate data for the valve groupings.
Therefore, it is acceptable for Susquehanna to have at least one valve from each group of check
~
valves included in the above relief requests to be tested at each refueling outage, and all valves in each group to be tested at least once every 8 years.
This maximum test interval is consistent with Subsection ISTC 4.5.4 of the 1995 Edition of the ASME OM Code for Operation and Maintenance of Nuclear Power Plants which the staff is proposing to endorse in its proposed amendment to 10 CFR 50.55a (62 FR 63892).
T
0 0
I
4.0 CONCLUSION
Based on the above evaluation, the NRC staff has determined that Revision 16 for Unit 1 and Revision 13 for Unit 2 to the Susquehanna Steam Electric Station lnservice Inspection Program Plan for Pump and Valve Operational Testing do not affect the validity of the relief requests and alternatives previously granted and authorized by the staff for the current 120-month interval.
Principal Contributors:
D. Terao D. Collins Date:
pctober 5,
] gg8
0 e
'~
~
4 ~
'1 l,